The |larynx|, or voicebox, is the opening of the |trachea| where it meets the |pharynx|. It's protrusion, with the |thyroid| ~cartilage~, can be seen in the exterior of the throat, and is commonly called the "Adam's apple." The |larynx| serves to close off the |trachea| during swallowing so that food is not admitted into the airway and facilitates swallowing by moving up against the back of the |tongue|. Containing the vocal cords, the |larynx| also enables vocalization by manipulating these cords to vibrate at a desired pitch when ~air~ is passed through the |larynx|. Three cartilaginous structures comprise the |larynx|: the cricoid, the |epiglottis|, and the |thyroid|. The circular cricoid ~cartilage~ serves to reinforce the head of the |trachea| to keep the airway open. The flap-like |epiglottis| helps to shut off the airway during swallowing, as it swings down to meet the upraised |larynx| to prevent food from entering the |trachea|. The |thyroid| ~cartilage~ forms the bulk of the structure of the |larynx|, anchoring the |epiglottis| by means of the false vocal cords, and by anchoring the true vocal cords to the vocal ~processes~ of the arytenoid ~cartilage~ of the glottis. The pitch of the voice is highly dependent upon the elasticity and tension in these true vocal cords. When the angle of the |thyroid| ~cartilage~ decreases in males during puberty, the tension on the vocal cords diminishes, resulting in a lower voice.
